Recommanded PCI-E Freq.

KHALIK · 30 May 2007 at 15:47

I am new to overlocking - pls help me with these questions.

Question 1
What should be the recommanded (safe) PCI-E x16 freq
(What are the benefits ?)

Question 2
What is the default PCI-E x16 freq. ?

E6600 cpu
GIGABYTE S3 Mobo
1gbx4 GEIL 6400 (800ghz) 4-4-4-12
GFX CARD BFG 8800 OC2 GTX

pc running stable at 3.2ghz (pime95)

voltage 1.45
fsb 400
multiplier x8
ddr2 0.3v

Able to reach 3.6ghz (under different settings x9 / v1.525) easily runs windows for hours (but not stable under prime95) temps below 52c (load)

Will_3rd · 30 May 2007 at 15:50

default is 100mhz and try and keep it there by locking the bus.

sidefxv1 · 30 May 2007 at 15:59

I've come across recommendations to lock it at anything from 100-120MHz, with claims that higher will give slight improvements in performance. In the end I've just settled on 105MHz and all seems good...

Cob · 30 May 2007 at 18:17

I keep mine at 105mhz. It helps the northbridge.

And anything over 115mhz severely increases the chances of hard drive corruption and even a dead graphics card.

Defcon5 · 30 May 2007 at 19:54

Cob said:
I keep mine at 105mhz. It helps the northbridge.

And anything over 115mhz severely increases the chances of hard drive corruption and even a dead graphics card.

Does it actually aid the NB in any way or was that just myth?

And whats the PCI-E bus got to do with HDDs?

El Jimben · 30 May 2007 at 20:01

Cob said:
I keep mine at 105mhz. It helps the northbridge.

And anything over 115mhz severely increases the chances of hard drive corruption and even a dead graphics card.

Yep, I screwed up my windows install by leaving the frequency on auto

Cob · 30 May 2007 at 21:19

Defcon5 said:
Does it actually aid the NB in any way or was that just myth?

And whats the PCI-E bus got to do with HDDs?

It's not a magic setting, but it does help squeeze the last few mhz out of the FSB and memory.

And PCI-E freq locks were introduced to motherboards to aid stopping the hard drive corruption that was being caused by raising the FSB in older boards.

easyrider · 30 May 2007 at 21:27

Always 101 since C2D arrived for me

Defcon5 · 30 May 2007 at 21:29

Cob said:
And PCI-E freq locks were introduced to motherboards to aid stopping the hard drive corruption that was being caused by raising the FSB in older boards.

Surely you mean the PCI freq

El Jimben · 30 May 2007 at 21:38

Defcon5 said:
Surely you mean the PCI freq

Nope because the PCI frequency is derived from the PCI-E frequency i.e. it's a third of it.

Defcon5 · 30 May 2007 at 21:42

El Jimben said:
Nope because the PCI frequency is derived from the PCI-E frequency i.e. it's a third of it.

So was PCI-E developed before PCI? Yet only used recently?

(Im not being argumentative btw, im just interested!

)

El Jimben · 30 May 2007 at 22:01

Defcon5 said:
So was PCI-E developed before PCI? Yet only used recently?

(Im not being argumentative btw, im just interested! )

Before PCI-E, I assume that the PCI frequency came from the AGP frequency i.e. 33MHz and 66MHz?

Chris Beard · 30 May 2007 at 23:01

El Jimben said:
Before PCI-E, I assume that the PCI frequency came from the AGP frequency i.e. 33MHz and 66MHz?

AGP also came after PCI. This does not mean PCI-E frequency cannot determine the PCI frequency as the bios is not as old as PCI.

V|per · 30 May 2007 at 23:18

i would assume it WAS originally pci frequency, then agp can along, and it was then agp frequency, now pci-e is here, it's called pci-e frequency...

braz2kuk · 30 May 2007 at 23:21

I have kept my PCI-E freq at 105mhz never had any problems

XtAsY · 31 May 2007 at 10:51

On my motherboard there is two PCIe frequencies. One says Northbridge PCIe 16x freq and this is at 125MHz. The other says Southbridge PCIe 16x freq and this is at 100MHz. Is this something to do with the fact the motherboard is SLI? It's a 680i board which has 3 PCI-E 16x (the one for physics runs at 8x though)

w3bbo · 31 May 2007 at 10:55

120mhz here.

EVGA 680i boards until recently had the PCI-E set at 125 (linkboost technology) but this was then disabled in future bios updates, no reason was given as to why.

Big.Wayne · 31 May 2007 at 11:32

I've always had my PCI-E speed at 100MHz, not seen or read any good reason why it should be higher except some people got a 'slight' boost to their 3DMark scores.

Somebody should do a comparison so we can see the benefit.

I'm not sure how the PCI-E bus affects hard drives? I know that if you don't lock the PCI bus to 33MHz you can loose your disks etc but not PCI-E?

CaNNoN_1981 · 31 May 2007 at 15:20

I have my pci-e freq on my DS3P set at 100 but i dont seem to have a pci freq option, checked every option on every screen.

Can someone enlighten me or is there just no option to set pci freq to 33 on this board??

Ta.

modo77 · 31 May 2007 at 16:39

Hmm, just tried upping it to 110 and the 3dmark05 score is lower than before (although its been a few weeks since i ran the one at 100). Nothing else has changed though:

PCI-E 100 17546
PCI-E 110 17442

Edit: PCI-E 115 17606

So read into that what you will :confused: